MySQL更新根據選擇

Question

SELECT 
    table_1.id, 
    (SELECT SUM(amount) FROM table_2 WHERE table_1.id = table_2.bid) AS sum_total 
FROM table_1 
WHERE table_1.total!=0 

我需要更新table_1.total，以便它等於sum_total。

任何adivce？

Answer 1

如下嘗試：

update table_1 as t1 left join (select SUM(amount) as totalamount ,id FROM table_1 group by id) as t2 on t1.id =t2.id 
set t1.total=t2.totalamount 

請不要要緊的變化。

Answer 2

這是否對你的工作：

 
UPDATE table_1 set total = (SELECT SUM(amount) FROM table_1 WHERE table_1.id = table_1.bid) AS sum_total) 

Answer 3

這個簡單的查詢應該工作得很好。

UPDATE 
    table_1 
SET 
    table_1.total = (SELECT SUM(amount) FROM table_2 WHERE table_1.id = table_2.bid) 
WHERE table_1.total!=0;